It is proposed that EEG topology differs in demented versus depressed groups of aged males during spatial and verbal task performance. Left and right hemisphere power spectra patterns elicited while performing verbal and spatial tasks will be compared to severity of depression and to cognitive and perceptual motor impairment as identified by MMPI, Halstead-Reitan Battery and Hamilton Depression Inventory. Specific hypotheses to be tested concerning depressive dysfunction: (1) resting frontal, temporal, and parietal lobe power spectra alpha region outputs are greater over right hemisphere than over left; (2) right/left parietal area alpha region power spectra ratio does not diminish significantly during spatial task; (3) left temporal area power spectra exhibits a significant shift to higher frequencies when a subject engages in a visually presented verbal symbol task. Specific hypotheses concerning dementia to be tested include: (1) resting frontal, temporal and parietal alpha outputs are greater over left hemisphere than over right; (2) right/left temporal area alpha power ratio does not diminish significantly during visual presentation of a verbal symbol task; (3) right parietal area power spectra activity shifts significantly from alpha toward beta region output during spatial task performance.